This disclosure relates generally to a sensor system, and more particularly to a sensor assembly for detecting a position of a moveable component.
Position sensing is often used to electronically monitor the position of a mechanical component. Position sensor assemblies, such as magnetic linear position sensors, are devices that provide a change in electronic signal strength that is proportional to the sensed movement of a mechanical component. For example, magnetic linear position sensors can monitor the position of various automotive components, including but not limited to, transmission shift rods, rotatable shafts, reciprocating levers, pedals or any other moveable members.
Sensor assemblies of this type typically include one or more magnets that generate a magnetic field having a magnetic field strength that varies as a function of position. The magnitude of the magnetic field strength is measured by an appropriate sensing device, such as a hall device, for example. The sensing device then generates an output signal, such as a voltage signal, that uniquely represents a specific position of a mechanical component relative to the magnetic field generated by the magnets of the sensor assembly.
A controller interprets the output signal communicated from the hall device and appropriately commands functionality in response to the interpreted output signal. For example, where the sensor assembly senses movement of a transmission shift rod of a vehicle, the vehicle controller interprets the output signal from the hall device and determines the gear that the vehicle transmission is operating in.
Designing sensor assemblies is often a complicated task. Many interdependent variables are involved in designing a sensor assembly for detecting a position of a moveable component that satisfies a customer's requirements with respect to stroke length (i.e., a total length of travel of the moveable component) and linearity. Linearity describes the graphic relationship between the linear positioning of the moveable component and magnetic field strength generated by the sensor assembly. A non-linear relationship between the linear positioning and the magnetic field strength can result in increased sensor assembly costs and complexity. Magnet material, height, thickness and length, gap distance between magnets, desired system stroke length, desired system field strength, as well as numerous other factors can affect the design capabilities of sensor assemblies. Known sensor assemblies have not adequately provided for variables in system stroke length, system field strength and linearity in all situations.